1. Field of the Invention
2. Description of the Related Art
The present invention relates to an injector for a vacuum evaporation source intended to evaporate or sublime materials in a vacuum deposition chamber.
Such a vacuum deposition chamber is used for the manufacture of CIGS (Copper Indium Gallium Selenium) solar cells or OLED (organic light-emitting device) diodes, for instance.
This vacuum evaporation source is particularly used to evaporate selenium for glass panel selenisation in horizontal top-down or bottom-up in line systems.
The document WO 2008/079209 discloses a known vacuum evaporation source intended to evaporate organic or inorganic materials for the fabrication of OLED diodes.
Such a vacuum evaporation source comprises a body attachable to a vacuum deposition system. The body comprises first and second body portions separable from each other. A valve is connected to an injector having a longitudinal shape and several exit orifices for diffusing the vaporized material. The injector is heated by heating means located on its external surface.
When the injector is used in horizontal bottom-up configuration, the nozzles are positioned in the bottom of the injector.
Each nozzle comprises a channel linking the interior and the exterior of the injector. The channel emerges inside the injector through the top face of the nozzle.
During the deposition process, a part of the vaporized materials is adsorbed and oxidized on the internal walls of the injector. Because of the variations of temperature, the oxidized materials become cracked. Some flakes of oxidized materials become detached from the wall of the injector and fall on the top face of the nozzles, leading to the clogging of a part of the nozzles.
The clogging of the nozzles leads to a non uniform spraying of the vaporized materials on the panels intended to be covered by the material.